1. Thallasemia major in which the defective gene is inherited from both parents. It is the most severe form, called Cooley's anemia.
2. Thallasemia intermedia is a mild Cooley's anemia.
3. Thallasemia minor where the defective gene is inherited from one parent and the other is a carrier. It may cause no symptoms, but changes in the blood may occur.
There are two types of thallasemia: alpha-thallasemia and beta-thallasemia.
Their names describe which part of the hemoglobin molecule that is effected, the alpha or the beta chain.
Alpha-Thallasemia
- Found in people whose hemoglobin does not produce enough alpha protein.
- Commonly found in: Africa, the Middle East, India, Southeast Asia, southern China, and occasionally the Mediterranean region.
Types of alpha-thallasemia:
There are four types of alpha thallasemia that range from mild to severe in their effect on the body.
alpha thallasemia major - all four alpha chain genes are deleted. It is so severe that death can occur
hemoglobin H disease - three alpha chain genes are deleted. Hemoglobin H disease occurs when a person has only one functioning alpha chain gene, resulting in a hemolytic anemia that can worsen with febrile illness or exposure to certain drugs, chemicals, or infectious agents. Persons with hemoglobin H disease are at increased risk to have a child with alpha thallesemia major, since they carry one #16 chromosome with an alpha chain two gene deletion (cis deletion).
alpha thallasemia carrier - two alpha chain genes are deleted, either:
both from the same #16 chromosome, called a "cis deletion"
one from both #16 chromosomes, called a "trans deletion"
when parents are carriers of the cis deletion, there is a one in four, or 25 percent, chance with each pregnancy, to have a baby with alpha thallasemia major.
silent alpha thallasemia carrier - one alpha chain gene is deleted (the other three are normal). Blood tests are usually normal and is the least severe out of all four types.
Beta-Thallasemia
- Found in people whose hemoglobin does not produce enough beta protein
- Commonly found in: Arabian Peninsula, Iran, Africa, Southeast Asia and southern China.
Types of beta-thallasemia:
There are three types of beta thallasemia that also range from mild to severe in their effect on the body.
beta-thallasemia minor - a person has one normal gene and one with a mutation. Lack of beta protein in this condition is not great enough to cause problems in the normal functioning of the hemoglobin. A person with this condition only carries genetic trait of thallasemia and will usually experience no health problems other than a possible mild anemia.
thallasemia intermedia - the affected person has two abnormal genes but is still producing beta globin. It is more severe than beta-thallasemia minor and may cause a moderately severe anemia.
thallasemia major (cooley's anemia) - this is the most severe form of beta thallasemia in which the person affected would have two abnormal genes that causes a complete lack of beta protein in the hemoglobin. This may lead to a life-threatening anemia.
Contents:Types of Thallasemia
Categories of Thallasemia:
1. Thallasemia major in which the defective gene is inherited from both parents. It is the most severe form, called Cooley's anemia.2. Thallasemia intermedia is a mild Cooley's anemia.
3. Thallasemia minor where the defective gene is inherited from one parent and the other is a carrier. It may cause no symptoms, but changes in the blood may occur.
There are two types of thallasemia: alpha-thallasemia and beta-thallasemia.
Their names describe which part of the hemoglobin molecule that is effected, the alpha or the beta chain.
Alpha-Thallasemia
- Found in people whose hemoglobin does not produce enough alpha protein.
- Commonly found in: Africa, the Middle East, India, Southeast Asia, southern China, and occasionally the Mediterranean region.
Types of alpha-thallasemia:
There are four types of alpha thallasemia that range from mild to severe in their effect on the body.
- alpha thallasemia major - all four alpha chain genes are deleted. It is so severe that death can occur
- hemoglobin H disease - three alpha chain genes are deleted. Hemoglobin H disease occurs when a person has only one functioning alpha chain gene, resulting in a hemolytic anemia that can worsen with febrile illness or exposure to certain drugs, chemicals, or infectious agents. Persons with hemoglobin H disease are at increased risk to have a child with alpha thallesemia major, since they carry one #16 chromosome with an alpha chain two gene deletion (cis deletion).
- alpha thallasemia carrier - two alpha chain genes are deleted, either:
- both from the same #16 chromosome, called a "cis deletion"
- one from both #16 chromosomes, called a "trans deletion"
- when parents are carriers of the cis deletion, there is a one in four, or 25 percent, chance with each pregnancy, to have a baby with alpha thallasemia major.
- silent alpha thallasemia carrier - one alpha chain gene is deleted (the other three are normal). Blood tests are usually normal and is the least severe out of all four types.
Source: http://www.healthsystem.virginia.edu/uvahealth/peds_hematology/thalapth.cfmBeta-Thallasemia
- Found in people whose hemoglobin does not produce enough beta protein
- Commonly found in: Arabian Peninsula, Iran, Africa, Southeast Asia and southern China.
Types of beta-thallasemia:
There are three types of beta thallasemia that also range from mild to severe in their effect on the body.
- beta-thallasemia minor - a person has one normal gene and one with a mutation. Lack of beta protein in this condition is not great enough to cause problems in the normal functioning of the hemoglobin. A person with this condition only carries genetic trait of thallasemia and will usually experience no health problems other than a possible mild anemia.
- thallasemia intermedia - the affected person has two abnormal genes but is still producing beta globin. It is more severe than beta-thallasemia minor and may cause a moderately severe anemia.
- thallasemia major (cooley's anemia) - this is the most severe form of beta thallasemia in which the person affected would have two abnormal genes that causes a complete lack of beta protein in the hemoglobin. This may lead to a life-threatening anemia.
Source: sections.php?sec=1//**|**//www.cooleysanemia.org/ sections.php?sec=1//**http://www.cooleysanemia.org/sections.php?sec=1
Cool website on Beta-Thallesemia
Picture of Alpha-Thallasemia Cells
Source:www.scielo.br/scielo.php?pid=S1516-8484200500...
Picture of Beta-Thallasemia Cells
Source: //www.bloodline.net/stories/storyReader$2344//
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